Atomkraftmikroskopie

Atomkraftmikroskopie is a term occasionally encountered in German-language discussions to denote microscopic techniques that image surfaces at atomic-scale resolution by measuring forces between a sharp tip and the sample. In mainstream scientific usage, however, the established term is Atomare Kraftmikroskopie (AKM) or Rasterkraftmikroskopie (RKM), commonly referred to as atomic force microscopy (AFM) in English. The phrase "Atomkraftmikroskopie" is therefore not standard and may reflect misnaming or broad, historical usage.

Principle and scope: AFM uses a cantilever with a nanometer-scale tip that interacts with the surface via van der Waals, electrostatic, magnetic, or chemical forces. A laser beam reflects off the cantilever onto a photodetector; the measured deflection or cantilever oscillation is converted into an image of surface topography and other properties. Modes include contact, tapping (dynamic), and non-contact; images can be obtained in air or liquid.

Instrumentation: Key components are the sharp tip, flexible cantilever, laser and photodetector, and a piezoelectric scanner controlling tip-sample position. Data can be complemented by measurements of friction, adhesion, stiffness, electrical conductivity, or surface potential.

Applications and limitations: AFM-based approaches are widely used in materials science, nanofabrication, biology, and nanotechnology to study surface structures, mechanical properties, and nanoscale phenomena. Limitations include tip convolution effects, sample damage in contact mode, relatively slow scan speeds, and sensitivity to environmental conditions.

History: The technique was developed in the 1980s by G. Binnig, C. F. Quate, and C. Gerber, and has since evolved with many variants and commercial instruments.